XIV Международная студенческая научная конференция Студенческий научный форум - 2022

The most effective way to increase engine power, without significantly changing its dimensions and weight, is to increase the density of air supplied to the engine cylinder for fuel combustion. By increasing the mass charge of the cylinder with air, that is, ultimately the oxidizer, it is possible to proportionally increase the amount of fuel that can be burned in the cylinder to generate thermal energy and then convert it into mechanical work. Due to the fact that the engine operating modes are constantly changing during the movement of the vehicle, in recent years, turbocharging control mechanisms have become widespread, which, in turn, can provide the optimal level of boost for a specific engine operating mode.

One of the control methods is the use of exhaust gas bypass or charge air by increasing the charge air pressure. In the second method, exhaust gas bypass is also used, only with the help of an oil automatic control system of the bypass valve. This particular adjustment method is characterized by a slightly higher efficiency, because with this method, the turbocharger is calculated from the very beginning for a lower flow rate.

For the designed engine, it is optimal to use boost control by means of exhaust bypass by increasing the pressure of the charge air.

This system has a number of advantages, we note the following.

Simplicity of design. Compared with the use of automatic control of the valve operation, it does not require additional use of oil and its pipelines, installation and monitoring of sensors, such as a pressure ratio sensor, is simpler in the design and calculation of the mechanism.

Economy. This option is more economical in terms of design and production costs due to the absence of mechanisms using oil regulation.

Compactness. The simplicity of the design and, as a result, its compactness, is an undeniable advantage today, since the engine compartment space in modern cars is very limited, and most of it is often occupied by many other various devices.

Bypass of the exhaust gas. It is characterized by a higher efficiency than the bypass of the charge air. This is due to the fact that the work is spent first on the rotation of the turbine, then the torque is transferred to the compressor, naturally, with some efficiency losses during the transfer of work, if after that a part of the charge air is drained, it will lead to a loss of efficiency, when the exhaust gas is bypassed, unnecessary work is not spent on the rotation of the turbine, as a result of which the efficiency of the turbocharger with the exhaust gas bypass is generally higher.

References:

1. Lukanin V.N., Morozov K.A., Khachiyan A.S., Alekseev I.V., Golubkov L.N., Chernyak B.Ya., Internal combustion engines, Theory of work processes: 3rd ed. - Moscow: Higher School, 2007. - 479 p.

2. Gotz, И.Мо . Kinematics and dynamics of the crank mechanism of piston engines: textbook / S. P. Gotz— - 3+ 's ed., sent messages > yes (yes). and, add. - Ii. : FORUM : INFRA-M, 2015. — 384 s